Apparatus for making meteorological observations



Oct. l. 1940. L.. F. CURTISS ET AL 2,215,151

APPARATUS FOR MAKING METEOROLOGICAL QBSERVA'TIONS 5 Sheets-Sheet l Filed July 11, 193e flaw/VA.: Qrfwpfwn ram? 1:1 E-m awww Q/.w/w @Maf/fon, @Legg/w Q wif/w,

L. F. CURTISS ET m.- 2,216,161 APPARATUS FOR MAKING METEOROLOGICAL OBSERVATIONS Filed July 11, 1935 5 Sheets-Sheet 2 6.5 l a /7// //4 64a I BY E ATTORNEY L. F. CURTISS ET AL APPARATUS Foa MAKING METEoRoLoGIcAL OBSERVATIONS Filed July 11, 1936 l sweets-sheet s ATTORNEY 0d. l. 1940- l.. F. cuR-rlss Er Al. 215,161

APPARATUS FOR MAKING METEOROLOGICAL OBSERVATIONS Filed July 11, 195e 5 sheets-sheet 4 1F.; zT-15 PRPs-SURE ATTORNEY Oct 1.\940 L. F. cuRTlss er AL 2,216,161 l l APPARATUS FOR MAKING METEOROLOGICAL OBSERVATIONS Filed July 11, 1936 5 Sheets-Sheet 5 35E- 1E v Patented Oct. l, 1940 UNiTED STATES APPARATUS FOR MAKING METEOROLOG- ICAL OBSERVATIONS Leon F. Curtiss, Garret Park, Md., and Allen V. Astin, Washington, D. C.

Application July 11, 1936, Serial No. 90,234

6 Claims.

Our invention relates broadly to systems of radiometeorography and more particularly to apparatus for making meteorological observations.

One of the objects of our invention is to provide means for automatically transmitting radio signals according to characteristics of surrounding media at elevations above the surface of the earth to observing stations.

Another object of our invention is to provide a system of radiometeorography in which a radio transmitter may be dispatched by a free balloon to the higher altitudes and automatically controlled by the characteristics of surrounding media for transmitting to observing stations, se-

quence signals which may be accurately interpreted for forecasting conditions of the weather.

Still another object of our invention is to provide a construction of lightweight automatic radio transmitter having means for controlling the transmission of sequence signals according to characteristics of surrounding media and registering said sequence signals at an observing station for permitting accurate forecast of weather conditions.

Another object of our invention is to provide an electrically and mechanically driven timing mechanism which may be elevated into the upper atmosphere for continuously controlling the transmission of sequence signals representative of weather conditions to observing stations on the ground.

A further object of our invention is to provide a construction of radio transmitter adapted to be elevated by means of a free balloon and automaticallylcontrollable according to temperature, barometric pressure, and/or humidity conditions for transmitting sequence signals to observing stations having means for interpreting the sequence signals to provide accurate determinations of -the said temperature, barometric pressure,

and/or humidity conditions existing in the path of travel of the free balloon.

A still further object of our invention is ,to provide a construction of radiometeorograph observation apparatus in which a permanent record of temperature, barometric pressure, and/or humidity conditions is made upon a tape by readings which may be interpreted to accurately indicate conditions of temperature, barometric pressure, and/or humidity existing at the measuring po- 'sition.

Other and further objects of our invention are to provide apparatus for making meteorological observations as set forth more fully in the specili-` cation hereinafter following, by reference to the accompanying drawings, in which:

Figure 1 diagrammatically andv schematically shows the electrical arrangement of the transmitter which is elevated by the free balloon for s transmitting sequence signals according to the characteristics of surrounding media to the observing stations; Fig. 2 is a diagrammatic and schematic view showing the radio receiving apparatus employed at an observing station includ- 10 ing the record perforating mechanism and the electrical circuit which controls the operation of the record perforating mechanism; Fig.l 3 illustrates a portion of the tape record 'on which the sequence signals indicating conditions of temper- 15 ature, barometric pressure,`and/or humidity at the measuring position are recorded on the tape record at the observing station; Fig. 4 is a cross sectional view taken through the radiometeorograph control mechanism with parts shown in 20 side elevation; Fig. 5 is a top partial plan view ci the mechanism shown in Fig. 4; Fig. 6 is a bottom partial plan View of the mechanism shown in Fig.

4 and illustrating the internal temperature measuring mechanism employed in the radiometeoro- 25 graph of our invention; Fig. 7 illustrates in top plan view the arrangement of the temperature control mechanism for measuring temperature in the surrounding media external to the housing within which the radiometeorograph is en- 30 closed; Fig. 8 is a vertical sectional View taken through the housing which encloses the radiometeorograph apparatus with equipment therein shown in elevation; Fig. 9 is a horizontal view through the housing taken -substantially on line 35 9--9 of Fig. 8 and showing certain of the equipment in top plan view; Fig. 10 is a fragmentary view illustrating the transmitter power supply circuit Vcontrol switch which is controllable from the exterior of the housing within which the radio transmitter and other parts of the radiometeorograph apparatus are substantially sealed; Fig. 11 is a side elevational View showing` the radiometeorograph apparatus elevated by a free balloon; Fig. l2 is a fragmentary perspective View of the upper end of the transmitting antenna doublet employed in association with the radiometeorograph apparatus and showing the manner of attachment to the free balloon; Fig. 13 is a plan View of the equipment employed at the observing 50 stati/on for interpreting the sequence signals recorded on the tape at the observing station;

Fig. 14 is an enlarged front elevational View of the apparatus for interpreting the sequence rea-dings on the tape record; Fig. 15 is a side eleva- 55 tional'view of the apparatus shown in Fig. 14 and illustrating the manner in which the tape carrying the sequence signals recorded thereon is applied to the measuring apparatus for interpreting the sequence signals recorded thereon; Fig. 16 is a perspective view of oneof the preformed plates against which the tape is applied in interpreting the records thereon; Fig. 17 illustrates a set of corrective preformed plates which are interychangeably attachable to the measuring apparatus for applying predetermined corrections under predetermined conditions forA interpreting the readings on Vthe tape; Fig. 18 is an elevational view of a modified form of radiometeorograph viewed from an opposite position with respect to the position in which Fig. 8 is taken; Fig. 19 is a horizontal sectional view of the form of radiometeorograph shown in Fig. 18, taken substantially on line I9-I9 thereof and with parts illustrated in top plan view; Fig. 20 is a vertical sectional view of the radiometeorograph taken substantially on line 20-20 of Fig. 18; and Fig. 21

shows schematically a form of electrically operated drive for the timing mechanism of the radiometeorograph.

Our invention is directed to a method and apparatus by which conditions of the weather may be forecast but whichavoids the expense and hazards to persons and property heretofore involved in taking observations by daily aircraft flights. The cost of weather observations by aircraft ights in certain localities has been estimated at a minimum of $750.00 daily. Loss of life and aircraft greatly increases such cost. In the system of our invention, we have developed a lightweight radio transmitter attached to a balloon by which a half Wave tuned doublet antenna with the radio transmitter attached thereto may be oatingly suspended in the air and allowed to ascend into the upper atmosphere. The radio transmitter is keyed by a control apparatus according to the characteristics of the surrounding media. with respect to temperature, barometric pressure, and/or` humidity. Signal impulses emitted by the transmitter are received at observing stations and translated to determine the temperature, barometric pressure, and/or humidity conditions at the measuring position. In developing the apparatus of our invention, we have been confronted with many obstacles, particularly the weight and size of the apparatus. We have succeeded in greatly reducing the size of the filament and plate batteries required. 'I'he complete apparatus for attachment to the balloon f weighs less than two pounds. Signals have been transmitted clearly at altitudes of 23 kilometers (14.3 miles) and at distances of 80 miles. A method of direction nding may be employed at two or more observing stations in picking up the signals emitted by the transmitter suspended from the free balloon. We provide for the transmission of a timing signal for indicating on a tape record at the observing station, predetermined intervals of time during which the time operated mechanism of the radiometeorograph is continuously operated. Sequence signals are emitted intermediate the transmission of the timing signals, the time of emission of the sequence signals with respect to the timing signals being directly controlled by the characteristics of temperature, barometric pressure, and/or humidity in the media surrounding the radiometerograph. Provision is` made for enclosing the radiometerograph wlthin a protective housing. Separate elements are provided for controlling the transmission of sequence signals both in accordance with temperature internally of the protective housing and temperature externally of the protective housing. At the observation station, the sequence signals are printed on the tape record and the tape record is then removed from the re- "corder and directly applied to a calibrated measuring device capable of directly interpreting the position of the sequence signals on the tape in terms of barometric pressure, temperature internal and external of the protective housing, and/or conditions of humidity.

In selecting a frequency band for radiometeorographs, simplicity of construction led to the adoption of the megacyclevregion for preliminary experiments. Such good results have been obtained that it seemed unnecessary to try other frequencies. It should be pointed out that the ultra-high frequencies are well suited to this work because of the absence of a reflected sky wave to complicate reception in producing fading and interfering with accurate direction finding. If one goes appreciably above 60 megacycles, however, difficulties are encountered in using ordinary commercial tubes, since the natural constants of such tubes play an important role in the oscillating circuits at these frequencies. The 60 megacycle region is free of this embarrassment while still retaining the ad- -vantage of using fairly short tuned half-wave doublet antennae and small coilsand condensers, thus reducing weight. In addition, very sensitive receivers of simple design are already available at this frequency.

The system of our invention has many advantages among which, we may mention:

(1) An instantaneous record of the observations is made as fast as the balloon ascends. Recovery of balloon and equipment is not necessary to obtain the record as is the case when self-recording instruments are sent up.

(2) Records may be obtained in any kind of weather. This is not true of the most common method of observation used at present, that of taking instruments aloft in airplanes.

(3) Observations may be made easily to any altitude up to 20 kilometers. Airplanes usually ascend only to about 5 kilometers for weather observations.

(4) The equipment required is much less expensive and observations can, therefore, be obtained more cheaply than by use of airplanes.

Referring to the drawings in more detail, reference character l indicates the doublet antenna employed in the transmitter of our invention. The antenna comprises a single wire element which, in the form of our invention illustrated in Figs. 8, 9, l1 and l2, is 2.7 meters long which makes a single turn indicated at 2 around the outside of the tuning coils indicated at`3 and I. This doublet antenna wire I is held taut by a light wooden .bow 5 shown more particularly in Figs. 11 and 12. The doublet antenna I hangs vertically with respect to the free balloon E from which the radiometeorograph and associated parts are suspended by member 1. The assembly of bow 5 and doublet antenna I is suitably stabilized with respect to suspension member 1 by cord member 8 having a loop 9 through which suspension member 1 passes. Opposite ends of the doublet antenna wire I pass through the wooden bow 5 andare secured around the ends of the wooden bow 5 as indicated at Ia in Fig. l2.

The radio transmitter comprises a push-pull oscillator Yusing two electron tubes which we have indicated generally at 10 and 11 in Fig. 1. In the particular form of our invention illustrated, We use two of the 30 type receiving tubes arranged for operation on 5 meters. The push-pull oscillator of the transmitter of our invention is more stable in frequency and is especially convenient since the two lamentary cathodes Illa and IIa provide the proper load for three dry cells connected in series indicated at I2. Furthermore, the radio frequency output of such an oscillator can be made relatively high by using a high plate voltage, particularly when signals are desired in short pulses so that there is no danger of overheating the plates. Moreover, the weight of the additional tube is small. The low filament drain of these tubes permits the use of small-size flashlight cells in the filament circuit.

Electron tubes I0 and I I include in addition to the lamentary cathodes IIJa and IIa respectively, the control grids I 0b and I Ib and the plate electrodes Ic and IIc. The plate electrodes Ic and IIc are connected to opposite ends of the inductance 3. The control grids I0b and IIb are connected to opposite ends of the inductance 4. Inductances 3 and 4 are Wound concentrically one over the other and insulated from each other by means of blocks of insulation represented at I4. The single loop 2 in doublet antenna I concentrically surrounds inductance coils 3 and 4 as illustrated in Fig. 8 and is insulated and spaced therefrom by insulation blocks I5. The self capacity of the coils is employed for tuning the,transmitting circuit. By precisely designing the coils 3, 4 and associating the coils in xed special relation as described, we have found that it is possible to adjust the transmitter circuit very closely to the desired frequency without resort to a tuning condenser, thus saving the Weight of the condenser structure under conditions where light weight is so essential. The plate and grid coils 3 and 4 are closely coupled and the coupling physically fixed as heretofore explained. The method of keying the transmitter circuit is highly important. Referring to Fig. 1, we have shown the cathode bias resistor I6 disposed between the point Il in the lamentary cathode circuit and the point I8 which connects through a series path containing resistor I9 to the tap 20 on the grid circuit inductance 4. A condenser 2I is connected in shunt with the cathode bias resistor I6. Condenser 22 is connected in shunt with resistor I9. The keying circuit connections are taken on opposite sidesof the cathode bias resistor I6 as represented lat v23 leading to the radiometeorograph control mechanism indicated generally at 24. When the radiometeorograph is connected as illustrated, cathode bias resistor I6 is shorted on each contact permitting about fifty milliamperes to ow in the plate circuit. By introducing the control mechanism into the transmitter circuit in this way, the contacts are always shunted by cathode bias resistor I6 and the voltage at the contacts is low, thereby eliminating danger of arcing or sparking. Also, this arrangement prevents any undesirable change in the tuning as the contacts are made or broken. The plate circuit is completed from a connection from the end I8 of cathode bias resistor I6 through plate battery 25 and choke coil 26 to tap 2'I on the plate circuit inductance 3. The transmitter is placed in operating condition by closing switch 28 in the filamentary cathode circuit 29. Switch 28 must be capable of operation from the exterior of the protective housing so that the transmitter may be placed in operation when the balloon is released for an ascension observation. As shown more particularly in Figs. 8-10, the radiometeorograph is contained within the multi-walled protective housing indicated generally at 3U formed on frame structure shown generally at 3I. The switch 28 is in the form of a plug 32 shown more particularly in Fig. 10 permanently connected to one side of the lamentary cathode circuit 29 and normally adapted torest in tubular .socket 33 when the transmitter is not in operation. When the transmitter is to be placed in operation upon release of the balloon, the plug 32 is removed from tubular socket 33 and is inserted in tubular socket 34 which connects to one side of the fllamentary cathode circuit 29 thus completing the circuit through the oscillator and initiating the circuit into operating condition.

For the purpose of reducing capacity effects and decreasing size and weight of the transmitter, we employ electron tubes IIJ and II without the usual pin base structures. The tubes are maintained adjacent each other in compact assembly by means of an insulated panel 35 adjacent the wire terminal ends of the tubes and by interconnecting means 36 adjacent the other ends of the tubes. The leads from the electrodes within tubes I0 and II are brought out upon insulated panel 35 and directly connected with the associated parts of the circuit illustrated in Fig. 1. 'Ihe condensers 2I and 22 and the resistors I6 and I9 are assembled in compact relation adjacent the panel 35 for decreasing the length of leads to a minimum.

The frame structure 3| supporting the enclosure 3l) includes the angularly disposed struts 3`I which support the electron tubes IIl and I I' with respect to bow 5. Laterally arranged shelf 38 extends through the enclosure and is supported by bow 5 and serves as a supporting means for the A battery I2 and the B battery 25 and as a supporting means for the timing mechanism indicated generally at 24. 'I'he struts 31 also provide means for supporting the electron tube assembly in position within the protective housing 30. The enclosing housing 30 has been generally described as multi-walled. We construct this housing very carefully from cellulose material which is stretched over the frame 3| withan external layer of cellulose material spaced from an internal layer of cellulose material. The ce1- lulose material is substantially'transparent, thus allowing light rays to pass freely through the protective housing. For the purpose of retaining heat rays which pass through the transparent wall structure of protective housing 30, we provide a metallic foil reflector illustrated at 43. The heat rays which pass through the transparent Walls of the protective housing 30 strike the metallic foil reflector 43 interiorly of the protective housing 30 and are reflected to a central position within the protective housing where the average temperature internally of the housing is measured by the control mechanism of the radiometeorograph. The entire front multi-walled panel of the housing 30 is removable to allow access to the mechanism within the housing. When the front panel is mounted in position, it is substantially sealed at the periphery by means of suitable gummed tape as shown at 40.

The housing thus formed protects the transmitter and the control means within the housing from the extreme low temperatures of the higher altitudes so that they may function with a high degree of stability and accuracy. The temperature within the housing is maintained higher than that of the surrounding atmosphere as the apparatus ascends by virtue of the double walled heat insulating construction of the housing, and heat losses are recovered by the absorption of radiant energy within the structure received by virtue of the transparency of the covering of the housing. The amount of heat recovered is measured by the action of the reectors 43 which provide additional radiant energy for absorption within the enclosure. In this manner temperatures of as high as 35 C. have been maintained within the enclosure during daytime operations While the outside temperature may be as low as -60 C. at altitudes of 40,000 feet or higher. Temperature measurement inside the enclosure is made in order that correction may be made in the results of the observations for errors introducedv by irregularity in the operation of the transmitter and control apparatus due to temperature variations in accordance with previous calibrations.

rIhe control mechanism of the radiometeorograph 24 is illustrated as including the time operated clock mechanism 45 mounted within the metallic band or 'strip 44 which encircles the time operated mechanism and forms a support for associated mechanism as will be hereinafter described. The time operated mechanism may be either spring actuated or electrically driven and is readily removable from and replaceable Within the protective housing 30 for adjustment and repair. 'Ihe removability of the wall 39 of the protective housing 30 as heretofore described permits insertion or removal of the control mechanism as required.

The time operated mechanism 45 drives a continuously moving sweep hand indicated at 46. The sweep hand 46 carries a resilient wire contact 4l on the end thereof which is adapted t0 make successive electrical connections with contacts connected in the keying circuit which wev have indicated at 23 in Fig. 1. The sweep hand 46 forms one side of the keying circuit While the contacts coacting therewith are connected at the opposite side of the keying circuit. The coacting contacts are insulated from sweep hand 46 by mounting means which we have shown generally at i suitably insulated from metallic band or strip 44 as indicated at 48. The mounting means 4l carries depending v.'ire contact members 49 and 50 disposed at spaced intervals and extending in the path of a resilient Wire contact 41 carried by sweep hand 45. As sweep hand 46 in the course of its rotation passes wire-like contact members 49 and 50, the control circuit 23 is closed successively for two distinct time intervals. That is to say, when contact 4l strikes contact Wire member' 50, the control circuit to the transmitter is closed for emitting a signal impulse and then immediately opened as contact 4l leaves contact Wire member 50 to be again subsequently closed as Wire element 47 engages contact wire 49, thereby transmitting successive timing signals and producing a permanent record on the tape of the recording apparatus shown generally in Fig. 2 and illustrated specifically in Fig. 3. The effector the timing signals on the tape record 5l is as illustrated at 52, 53 and 54, that is, recurring impressions or perforations on the tape 5|, illustrating the lapse of uniform time intervals assweep hand 46 is continuously driven by time operated-mechanism 45. -"f I-'he mounting means 4I includes a central bearing in which a multiplicity of concentrically disposed sleeve members are journaled.

For purposes of explaining our invention, we have shown three concentric rotatable members journaled in bearing 55, but it will be understood that any additional number of rotatable members may be employed for securing measurements of other characteristics as will be hereinafter described in more detail. The rotatable members are illustrated as comprising rod member.56, concentrically arranged sleeve 5l and concentrically arranged sleeve 58. Each of the sleeves are arranged for independent angular rotation and each sleeve carries an actuating arm 56a, 51a, and 58a for effecting such angular adjustment according to variations in characteristics to be measured. Each of the separate rotatable members 56, 5l and 58 carry adjustable contact arms which we have illustrated at 56h, 51h and 58h.

'Ihe separate actuating arms 56a, 51a, and 58a are each controlled by means of motion transmitting members 59, 60 and 6l by separate devices responsive to changes in condition of surrounding media. For example, motion transmitting member 59 connects between actuating arm 456a and the end of angularly shiftable lever 62 pivoted on member 63 supported from the mounting means 4l. The angularly shiftable lever 62 has an extended end 62a which is engaged by lever member 64 pivoted to band or strip 44 at 65. The end of lever 64 extends on the other side of the fulcrum 65 as indicated at 64a .and is engaged by the end 66 of the bimetallic thermal element 61. The bimetallic thermal element 61 is secured at one end to the support 68 which projects from the strip 44. Thebimetallic thermal element 6l is subjected to the temperature within the protective housing 30. Changes in such internal temperature arising as a result of the passage of the suns rays and light rays through the transparent multi-walled structure of the protective housing, as reflected by the metallic foil reflector 43, serve to effect displacement of thermal element 61, imparting movement to the' end 66 of thermal element 61, angu- -larly displacing lever 64, imparting movement to the end 62a of lever 62, and transmitting movement through motion transmitting means 59 to actuating arm 56a and correspondingly turning rotatable member 56 for advancing or retracting the adjustable contact arm 56h in the path of the contact 4l carried by sweep hand 46.

The pressure element shown at .'l is suitably supported with respect to band or strip 44 and is subjected to atmospheric pressure within housing 3U. The variations in pressure are trai-1smitted through leverl member l2 pivoted aiJ i3. The inner end of lever member 'l2 indicated at 12a is connected to the actuating member 74 projecting from the pressure element 10. The movements due to variations in pressure transmitted through motion transmitting lever l2 are imparted to the end 15a of lever 15. Lever l5 is pivoted at 'I6 with respect to strip 44 and transmits movement to the end 11a of lever 11. Lever ll is pivoted at 18 on mounting means 4l. The end of lever l1 indicated at 'Hb is connected through motion transmitting member 6I to the end of actuating arm 58a. Rotary movement is imparted through arm 58a to rotatable sleeve 58 and from thence to contact arm 58h. Contact arm 58h has the end thereof projecting in the path of contact member 41 carried by sweep hand 46. As the pressure varies, the contact arm 58h is advanced or retractedin the path of the contact member 41 carried by sweep hand 46.

, is enabled to respond to the average external In order to measure temperature external to the protective housing 30, We provide a supporting member attached to the strip 4| and projecting through the side wall of the protective housing 30. The member 80 provides a mounting means for a bimetallic thermal element indicated at 8| -having one end fixed to the support 80 and the other end connected to a lever 82 free to swing about a pivot 83 as a center in accordance with the expansion or contraction of the bimetallic spiral element 8|. The lever 82 which is angularly driven by the expansion or contraction of bimetallic thermal element 8| has the end thereof connected through motion transmitting member 60 which extends through the Wall of the protective housing 30 and connects with the end of the actuating arm 51a. The arm 6|) is suitably o set as indicated at 60a to allow movement thereof Without interference with any of the parts of the associated mechanism. Variations in temperature external to the protective housing 30 cause movement ofrmotion transmitting member 6D serving to angularly displace actuating arm 51a and revolve rotatable sleeve 51h for correspondingly shifting contact arm 51h and advancing or retracting the contact arm in the path of the contact element 41 carried by sweep hand 46. Changes in external temperature, accordingly, serve to advance* or retract contact arm 51h in the path of sweep hand 46 thereby deterniining the time of transmission of a signal impulse representative of external temperature with reference to the timing signal.

`In order that the external temperature may be accurately measured we provide' a stack of metallic foil shown at 88 surrounding the spirally arranged thermal element 8|. The stack 88 is open at both ends and extends substantially the vertical height of the housing 30. 'I'he stack 88 is supported immediately adjacent the frame 3| and is disposed between the laterally projecting apex portion of the frame as shown in Figs. 8 and 9. The stack 88 is maintained in position by a pair of members projecting laterally from frame 3| and embracing the stack 88. Members 89 are attached at one end to frame 3| as indicated at 89a and at the other end to the stack 88. The stack 88 substantially prevents the direct rays of the sun from falling upon the thermal element 8| due to the shielding action thereof and thus, because of the average temperature which stack 88 assumes, the thermal element 8| temperature with a high degree of precision.

In order to allow passagel of the supporting member 80 and the motion transmitting member 60 through the wall of the protective housing 30, and through the side wall of stack 88, suitable relatively narrow slots `19 and 90 are provided. Before an' ascension, slots 19 are closed as nearly as possible by strips of adhesive tape secured to the side wall structure of the protective housing 38. The slots through the protective housing 30 through which the doublet antenna extends as indicated at are also maintained as small as practicable by means of suitably fitted patch members applied to the wall of the housing.

The protective housing 3|) is centrally supported through a plate member 86 extending be-- heath the top portion of the frame 3| of protective housing 30 and connected through rod member 81 to the supporting member 1 connected to the free balloon 6.

The device for measuring humidity may be readily applied to the control mechanism and an 48 operates.

additional contact arm journaled in the rotatable assembly and shifted to selected positions in the path of the contact element 41 as conditionsl of humidity change for thereby controlling the transmission of sequence signals.

In Figs. 18-21 we have illustrated a modified Aform of the apparatus of our invention wherein the bow 5 is eliminated and the doublet antenna is moved to the center of the housing 30 and serves not only as the antenna but also as the The upper portion of doublet connects lwith the member 1 suspended by the balloon 6. A similar double wall transparent cellulose structure is provided for the housing with a removable side 39 as heretofore described. The transmitter and the time operated mechanism 24 are supported' byfta4 suitable laterally extending shelf |5| as shown. The doublet has the lower portion thereof extending through a central aperture |52 in shelf |5|. The transmitting apparatus, batteries and the time operated mechanism are distributed in such manner as to balance the housing during ascension.

As we have heretofore noted the time operated mechanism may be either spring driven or electrically driven. Fig. 21 shows an arrangement of an electrically driven time operating mechanism. A light Weight motor is supported on band orstrip 44 through frame |53 which serves asa field magnet for the motor having armature |54 journaled in bearings |55 and |56. The commutator |51 on the armature shaft coacts with brushes |58 through which energy is supplied from battery |59 for driving the motor when starting switch |60 is closed. We have found that a motor of size and weight within the limitations allowed may be driven from a battery of the size and weight allowed for a period of approximately six hours which is adequate for purposes of the observations for which the apparatus of our invention is required. A pinion |6| carried by the motor shaft engages a gear |62 mounted on the shaft with the sweep hand 46 and serves as a speed reduction gear system for driving the sweep hand 46 at a predetermined uniform rate. Suitable mounting means |63 is provided for the journal in which the sweep hand The electrical and spring driven mechanism may be employed interchangeably.

At the observing stationwe provide a high frequencysignal receiving system indicated dlagrammatically in Fig. 2. The receiving antenna and ground connection is shown connected to the ultra-high frequency pre-amplifier 9|. The output of the ultra-high frequency pre-amplifier 9| connects tothe ultra-high frequency resistancecapacity coupled superheterodyne receiver indicated at 92. The output of the receiver 92 connects to the resistance coupled pulse amplifier 93. The pulse amplifier 93 has its output connected to the thyratron control circuit indicated generally at 94. The control relay 95 operates an armature in accordance with the received signal impulses which controls the potential upon grid 96h of thyratron 96. The thyratron 96 contains cathode 98a, grid 96h, and anode 96C. The output circuit of thyratron 96 contains actuating winding 91 of the punch control solenoid and the alternating current power source indicated generally at 98. The punch control solenoid 91 operates an armature 99 which controls the tape perforator mechanism shown generally at |00. The tape perforatormechanism includes a housing IOI which carries a tape guide |02 adjacent the base slotted to allow the tape 5| to be moved therethrough. The punch housing has a punch member |04 extending therethrough guided by means ,of the apertured head |05 and guided through the detachable head |06. The punch member |04 has a ange |01 thereon against which the spiral spring |08 acts to normally maintain the punch member |04 in elevated posi-- tion ready to be moved to perforating position as armature 99 is attracted by solenoid 91, whereupon punch member |04 cuts through the tape 5| forming a perforation therein. The perforations in the tape 5I formed upon receipt of the timing impulses have already been explained and indicated at 52, 53 and 54 in Fig. 3. As the contact arm between contact arm 41 and contact arm 58h is the first contact which is made after sweep hand 46 passes timing contacts 49 and 50, the first signal impulse will be an indication of pressure and, as represented in Fig. 3, tape 5| will be perforated at |09 to indicate a pressure reading. Contact arm 41 will next make connection with contact arm 56h providing a reading of internal temperature as indicated by perforation ||0 in tape 5|. Contact element 41 carried by sweep hand 46 then makes connection with contact arm 51h providing a reading of external temperature and forming a perforation I|| in tape 5|. The timing impulses are next received as indicated by the perforations 53 in the tape 5| The measurements are then repeated and perforations obtained in succession at ||2 for indicating pressure conditions, ||3 for indicating internal temperature, and II4, for indicating external temperature.

The sequence signals are repeated. Each successive reading may vary considerably from the earlier readings and the position of the perforations may be advanced or retarded along the tape, the distance and spacial relation of such perforations providing an accurate measure'of the conditions at the measuring position. It will be clear that a.measurement with respect Vto humidity conditions will also appear as a perforation on the tape upon lreceipt of a sequence signal, depending u'pon conditions of humidity by the addition gf the necessary arm and contact device controlled thereby as heretofore explained.

In order to interpret the sequence readings on the tape 5|, we provide a special apparatus represented xin Figs. 13-17. A flat supporting surface ||5 provides a carrier for a. curve chart IIB. Complementary sets of substantially semi-circular members I |1 are arranged to be detachably mounted adjacent the at supporting surface I I5 on opposite sides of laterally projecting lug members IIB projecting from the bracket I9 which is secured adjacent the peripheral edge of the supporting surface H5. The curved-peripheral edges of the complementary members I |1 provide a support against which the paper tape 5| is adapted to be laid. The sets of curved peripheral members I I1 form parallel extending flat surfaces between which the projecting end of arm |20 is adapted to swing. The arm |20 is fulcrumed at |2| in bracket I9 and has a forwardly extending portion 23 adapted to sweep over the curve chart ||6 and a rearwardly extending portion |24 adaptedto sweep between the parallel extending surfaces off the complementary members ||1. The end of the arm |20 terminates in a pin |25 adapted toenter perforations in tape 5I. The arm |20 is normally biased to a predetermined position with respect to curve chart I6 by means of hat spiral spring I 26 which extends between the 4axis member on which arm |20 is supported and 'the bracket I9. The forwardly extending portion of arm |20 is calibrated on each side thereof, the scale on one side indicated at |21 readingin terms of temperature and the scale on the opposite side indicated at |28 reading in terms of pressure. Predetermined curves shown at |29 and |30 and |3|, prepared on the curve v chart II6, are standardized for cooperation with the calibrated scales |21 and |28 so that upon angular movement of arm in any position over curve chart I |6, the temperature or pressure reading may be directly determined by reading the intersection of the curves |29, |30 or |3I with the calibrated scales |21 or |28 respectively. The method'of angular interpretation of the sequence readings on the tape record 5| is carried out by attaching lthe tape record 5| at a position adjacent the set of curved members ||1 as indicated at |32. A pin |33 is located at the position |32 on one of the members |I1 and projects through the rst of the timing perforations 52 in tape 5I. The tape 5| is then stretched around the curved peripheral edges of members `I I1 and the sequence perforations successively placed over pin |25 allowing the arm |20 to be moved to a position where tape 5| is drawn taut against the peripheral edges of members ||1 allowing a reading to be made of the particular sequence signal, the reading being determined by observing the intersection of the respective calibrated scales with the representative curves on chart IIS. That is to say the pin |25 may be projected through the pressure perforation |09 and arm |20 swung to a limiting position and the reading immediately interpreted by noting the intersection of scale |28 with pressure curve |29. Correspondingly, pin |25 may be projected through perforations ||0 and respectively and successive readings taken afterarm I 20 has been swung to stretch the tape 5| taut by observing the intersection of scale |21 with the internal temperature curve |30 or the external temperature curve I3I respectively. In this way rapid interpretations. of the readings on the tape may be effected. As the spacial relation of the perforations along the length of the tape from the perforations representing timing impulses varies, changes in the readings may be readily noted from the scale readings as heretofore explained.

It will be readily understood that a curve showing humidity conditions may be added to the curve chart for similarly interpreting perforations on the tape representative of humidity conditions.

Because of the many variables involved, we iind it necessary to prepare several sets of complementary members ||1 as indicated in Fig. 17 at |I1a and |I1b of varying radii to be used for making readings over differing temperature pressure or humidity ranges. To allow quick interchange of the sets of complementary members adjacent the chart IIS we provide slots in the peripheral edges of the complementary sets of members |I1`as indicated at II1, |I1a and ||1b respectively which coact with the quick removable wing nut devices |34 which engage bolts |35 extending through the projecting lug members II8. For making readings under differing conditions,

the wing nuts i3d may be removed, the bolts |35 withdrawn, the set of complementary members H1 removed and the desired set substituted and the bolts again replaced and the wing nuts |34 secured in position.

We have found the system of our invention highly efiicient and practical in the determination of meteorographic data. We appreciate,

however, that modifications may be madeV in the A method and apparatus employed and it is not our intention to limit our invention 4to the particular form disclosed herein. We intend no restrictions upon our invention other than may be imposed by the scope of the appended claims.

What we claim as new and desire to secure by Letters Patent of the United States is as follows:

1. Meteorological apparatus comprising a frame structure, a substantially transparent enclosure carried by said frame structure, means for concentrating light rays and the heat incident thereto within said enclosure, a radio transmitter carried by said frame structure and mounted Within said substantially transparent enclosure, an opaque tubular member open at the ends supported by said frame structure externally of said substantially transparent enclosure, and a control device mounted in said tubular member and operating to control the transmission of signals from said radio transmitter within said enclosure, the transparency of said enclosure permitting the passage of light rays therethrough and the opacity of said tubular member excluding light rays to effect desired different temperature conditions in said housing and said tubular member.

2. Meteorological apparatus comprising a frame structure, a substantially transparent enclosure carried by said frame structure, means for concentrating light rays and ,the heat incident thereto Within said enclosure, a radio transmitter disposed within said enclosure, a device mounted adjacent said radio transmitter for controlling the operation of said radio transmitter according to meteorological conditions withinsaid enclosure subject to the effect of light rays admitted thereto, a support extending from said frame structure, an antenna mounted on said support and connected with the radio transmitter within said enclosure, and means for fioatingly suspending said enclosure and effecting the ascension thereof into the upper atmosphere.

3. Meteorological apparatus comprising a frame structure having substantially transparent Walls for the passage of light rays therethrough, a radio transmitter mounted within said frame structure, control means in ounted adjacent said radio transmitter for controlling the operation thereof according to meteorological conditions within said frame structure subject to the effect of light rays admitted thereto, means for concentrating light rays and the heat incident thereto within said frame structure, and means for fioatingly suspending said frame structure and effecting the ascension thereof.

4. Meteorological apparatus' comprising alightweight frame structure adapted tovbe elevated into the upper atmosphere, transparent wall members for said frame structure for permitting the passage of light rays therethrough, a lightweight radio transmitter mounted within said frame structure, controlmeans mounted adjacent said radio transmitter for controlling the operation thereof according to meteorological conditions within said frame structure subject to the effect of light rays admitted thereto, and means carried by said frame for concentrating light rays and heat incident thereto within said frame structure.

5. Meteorological apparatus comprising a frame structure having a do'ible wall of transparent cellulose material, transverse supporting means in said frame structure having a radio transmitter including battery sources of power and control means mounted thereon, said control means comprising a rotatable contact driving mechanism and a plurality of movable contact actuating means operable in accordance with meteorological conditions, Ya portion of the wall of said frame structure comprising a block member apertured adjacent said control means, one of said actuating means being disposed exterior of said frame structure and connected with said control means through said apertured block member, means for floatingly suspending said `frame structure and effecting elevation thereof into the upper atmosphere; said double walled .frame structure being effective substantially to insulate said transmitter, said battery sources of power and said control means from external temperature conditions; and a reflector foil lining of the lower portion of the inner wall for concentrating light rays and the heat incident thereto within said frame structure.

6. Control apparatus for a signal transmitter adapted to be carried by a iree balloon which comprises a frame, a watch type driving mechanism and a drum type barometric pressure device mounted in spaced parallel relation in said frame, a rotatable contact driven by said driving mechanism in a plane parallel to said driving mechanism, a movable contactdisposed in the path of said rotatable contact and adjustable coaxially therewith, and link-means disposed on said frame and connected between said movable contact and said barometric pressure device for actuating said movable contact, said link means including crank means for converting the `axial movement of said drum type device into circumferential movement for actuating said movable contact.

LEON F. CURTISS. ALLEN V. ASTIN. 

